Quantitative electronencehalography is a valuable, safe tool in the study of brain electrical activity which is reflective of various mental states and functions. Quantitative EEG has been successfully applied in the field of neurology, neurosurgery and recently, biological psychiatry for the diagnosis and assessment of psychopathologies (e.g.schizophrenia, depression) and drug effects on the brain. The latter application has been labeled pharmaco-EEG and has shown great promise in assessing bioavailability, drug response classification and in predicting the effectiveness of psychotropic drugs. Pharmaco-EEG is emerging as a major new avenue of clinical and scientific evaluation of the biological basis of psychiatric disorders. Quantitative EEG procedures do, however, place considerable demands on hardware and software systems due to the large number of recording channels employed (typically 16-32 channels), the large size of data files collected and the complex mathematical procedures required for analysis. Currently-marketed quantitative EEG systems for such applications range in price from $39,000 to $84,000 and are consequently not widely available to the scientific or clinical communities. Phase I is designed to develop a low cost (less than $7,000) EEG systems module that could be added-on to any IBM-AT or AT- compatible microcomputer. This proposed innovation relies on incorporation of state-of-the-art integrated circuit technology and data processing methods. The system will be designed and developed in close collaboration with the World Health Organization to ensure standardization of data acquisition, analysis and transfer procedures. In Phase I, the proposed system will be tested by collecting and analyzing 20-channel EEG scans in 10 schizophrenic subjects both prior to and during drug administration. In Phase II, a broad of internationally recognized experts in the field of electroencephalography, including pharmaco-EEG, will be brought together to establish standardized hardware and software specifications for full-scale development and refinement of the proposed system. A comprehensive array of user-friendly features would be added to the system. In Phase II, the establishment of an international EEG/Evoked potential data base for the field of pharmaco-EEG through collaboration of participating W.H.O center in 5 countries would begin.